|Title||Observations and diagnostic tools for data assimilation|
|Publication Type||Education material|
|Secondary Title||Meteorological Training Course Lecture Series|
|Keywords||lecture notes, NWP|
The purpose of the observation preprocessing and screening is to produce a clean array of observations in an easily accessible format to be used in the data assimilation. At the preprocessing stage an array in a suitable format is created for the data assimilation. Observation screening then selects a subset of observations to be presented for the assimilation itself. After the assimilation step a feedback file is created using the preprocessing software. This file contains all the relevant information regarding the use and impact of observations in the assimilation. This enables detailed diagnostic studies to be carried out afterwards on the performance of the assimilation and observing systems.